<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="p">
    </div>
    <script>
        var interval = setInterval(
            function () {
            var p = document.getElementById("p");
            var date = new Date();
            var pp = date.getHours()+":"+date.getMinutes()+":"+date.getSeconds()
            p.innerText = pp
        },1000
        )
    </script>
</body>
</html>